$(document).ready(function(){
	var top=speed=0;
	var delay = -2;
	$('.fly').each(function(){
		top = 0.8*Math.random();
		delay = delay+Math.random()+1;
		speed = 8*(Math.random()+1);
		$(this).delay("100").css({
			'top': top*100+'%',
			'animation-delay':delay+'s',
			'-webkit-animation-delay':delay+'s',
			'animation-duration':speed+'s',
			'-webkit-animation-duration':speed+'s'
		});
	})
	

})